Napoleonville, Louisiana has a Humid Subtropical Climate climate (Köppen classification: Cfa). Average annual temperatures range from 15.1 °C (low) to 25.6 °C (high). Annual precipitation averages 1631.4 Millimeters. Napoleonville is located in USDA Plant Hardiness Zone 9b. The growing season typically runs from the last frost around Feb. 1 - Feb. 10 through the first frost around Dec. 11 - Dec. 20.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | 6.1 °C | 16.9 °C | 149.1 mm |
| February | 7.9 °C | 19 °C | 106.93 mm |
| March | 11.2 °C | 22.3 °C | 105.41 mm |
| April | 14.6 °C | 25.6 °C | 126.24 mm |
| May | 19 °C | 29.2 °C | 149.86 mm |
| June | 22.3 °C | 31.6 °C | 192.79 mm |
| July | 23.4 °C | 32.5 °C | 165.86 mm |
| August | 23.2 °C | 32.7 °C | 169.42 mm |
| September | 21.2 °C | 30.9 °C | 136.4 mm |
| October | 15.4 °C | 26.9 °C | 111.25 mm |
| November | 9.8 °C | 21.8 °C | 104.9 mm |
| December | 7.1 °C | 18.2 °C | 113.28 mm |
| Annual | 15.1 °C | 25.6 °C | 1631.44 mm |
| Average First Frost Date | Dec. 11 - Dec. 20 |
| Average Last Frost Date | Feb. 1 - Feb. 10 |
| Average Days With Frost | 10-20 Days |
| Plant Hardiness Zone | Zone 9b : -3.9°C to -1.1°C |
| Plant Hardiness Zone - 2012 | Zone 9a : -6.7°C to -3.9°C |
| Current Drought Conditions | Normal |
| Köppen Climate Classification | Cfa - Humid Subtropical Climate |